能效最优准则下无人机空中高度的优化算法

Optimal Energy Efficient Based Aerial Altitude Optimization of Unmanned Aerial Vehicle

利用无人机(unmanned aerial vehicle,UAV)组建空中移动基站,可为地面终端用户提供更灵活、高效的接入服务。受UAV覆盖范围和有限能量的约束,研究如何建立能效最优的UAV部署算法至关重要。为此,提出能效最优准则下无人机空中高度的优化算法(optimal energy efficient based aerial altitude optimization,EEAO)。先在满足用户最小速率要求和UAV高度的约束条件下,构建能效最优的高度优化的目标函数。同时,定义能效时不仅考虑UAV的通信能耗,还考虑UAV在垂直爬升和悬停阶段的能耗。再分别利用和序列凸规划法(sequential convex programming,SCP)和单调分式规划法(monotonic fractional programming,MFP)求解目标函数,获取能效最优的UAV高度值。性能分析表明,基于SCP法求解的最优高度值与基于MFP法求解的最优高度值相近。同时,相比于不考虑悬停阶段UAV的能耗,考虑悬停阶段UAV的能耗可提升网络能效。

Utilizing a unmanned aerial vehicle(UAV) to build aerial mobile small cell can provide more flexible and efficient services for ground terminal users.Constrained by the coverage and limited energy of the UAV,it is necessary to study how to build an optimal energy efficient based deployment of UAV.Therefore,objective function is constructed that maximizing the global energy efficiency,subject to altitude and minimum individual date rate constraints.When maximizing the energy efficient,both energy required for communication and energy consume by aerial vehicle,including the energy consumed by the rotor of UAV during climbing and hovering.Sequential convex programming(SCP) and monotonic fractional programming(MFP) are used to solve the objective function.Numerical results show that solution obtained from SCP is the same as the optimal solution form MFP.In addition,there is a gain in energy efficient when the UAV is hovering at an optimal altitude determined by considering the non-zero roto energy consumption of UAV.